The term neo-Nazi refers to any post-World War II social or political movement seeking to revive Nazism, or some variant that echoes core aspects of National Socialism. Members of neo-Nazi groups (excluding the NSM) prefer to be called "white nationalists, white separatists, or, white racialists," and object to the term neo-Nazi. The vast majority of neo-Nazis have beliefs that differ from actual Nazism, but they still advocate white supremacy.

During the 1960-70s, all racist non-Klan groups were labeled generically as neo-Nazis, and so were the racist skinhead groups that emerged during the 1980s. The Ku Klux Klan started as a domestic "homegrown" hate movement, and was not directly influenced by Nazi ideology.

There are a number of small neo-Nazi groups in the United States today. The earliest example of this ideological tendency can be traced back to the 1930s and the formation of the German-American Bund. The German-American Bund and similar groups achieved limited popularity. The zenith of the Bund's history occurred on President's Day, February 19, 1939 at Madison Square Garden in New York City. Some 20,000 people attended and heard Fritz Kuhn criticize President Franklin D. Roosevelt by repeatedly referring to him as “Frank D. Rosenfeld”, calling his New Deal the "Jew Deal." The Bund's popularity rapidly faded with the onset of World War II. The groups either disbanded or were dismantled by force of law (such as the 1942 sedition trial) during the war period. After the war, new organizations formed, with varying degrees of support for Nazi principles.

George Lincoln Rockwell

In 1959, the first explicitly postwar American neo-Nazi group was founded by George Lincoln Rockwell. The American Nazi Party achieved high-profile coverage in the press through their public demonstrations.

American Nazi Party

Organizations which report upon American neo-Nazi activities include the Anti-Defamation League and Southern Poverty Law Center. While a small minority of American neo-Nazis draw public attention, most operate underground, so they can recruit, organize and raise funds without interference or harassment. American neo-Nazi groups often operate websites, occasionally stage public demonstrations, and maintain ties to groups in Europe and elsewhere.

NSM Commander Jeff Schoep

The First Amendment to the United States Constitution guarantees freedom of speech, which allows political organizations great latitude in expressing Nazi, racist, and anti-Semitic views. A First Amendment landmark was the "Skokie Affair", in which neo-Nazis threatened to march in a predominantly Jewish suburb of Chicago. The march never took place in Skokie, but the court ruling allowed the neo-Nazis to stage a series of demonstrations in the Chicago area.

Members of The Order were convicted of crimes such as murder, racketeering, conspiracy, violating civil rights and sedition. Matthew F. Hale of the Creativity Movement was imprisoned for soliciting the murder of a federal judge. Aryan Nations lost a $6.2 million dollar lawsuit after Aryan Nations members opened fire on a passing vehicle. Aryan Nations has since lost its headquarters and paramilitary training grounds, and has split into three separate organizations. Other neo-Nazi groups in the US, include the National Alliance, White Aryan Resistance (WAR), American Front, and the National Socialist Movement (NSM). The NSM was founded in 1974 by Robert Brannen, former member of the American Nazi Party before its decline. The group claims to be the largest and most active neo-Nazi organization in the United States.

Combat 18 (C18) is a neo-Nazi group based in the UK. C18 is an international group with chapters in Europe, South America, Australia, Canada, and the US. A former C18 leader, Del O'Connor, moved to the US and started TCB Hate Crew, a small skinhead group in Texas and parts of the Midwest (now defunct). Del O'Conner and his C18 splinter group, White Wolves, were initially believed to have been involved in masterminding the bombing of a gay nightclub and several other locations in London. He is now a representative for the group Volksfront.